The Division of Cardiothoracic Surgery at the Keck School of Medicine of USC and the University of Southern California, with its collaborators throughout the University, is committed to becoming a Core Clinical Center (CCC) for the Cardiothoracic Surgical Trials Network (CTSN). The specific aim of this research proposal is to describe the experience, expertise, collaborative nature, and resources available at the Keck School of Medicine of USC and the University of Southern California that will substantially contribute to the success of the CTSN. We believe that our program is ideally suited to participate in the CTSN as a CCC for the following reasons: (1) the University and Division's commitment to excellence in patient care, research, education, and innovation; (2) Demonstrated commitment to the CTSN by the Division, Principal Investigator and Co-lnvestigator as a CTSN Satellite Site since 2010; (3) our robust cardiothoracic surgical practice which performs nearly 1000 major cardiac surgical procedures each year; (4) our unique location in Los Angeles and access to the LAC+USC HealthCare Network, which provides access to a racially, ethnically, and socioeconomically diverse population, with an especially large Hispanic population; (4) our demonstrated ability to identify, recruit, randomize, and retain patients from our large patient population; (5) our extensive history of clinical and surgical excellence and innovation and prominent position in cardiovascular care; (6) the demonstrated excellence of our clinical research unit which over the last five years has enrolled over 500 patients in clinical cardiothoracic surgery trials and maintains an active observational registry o over 2600 patients; (7) and our ability to coalesce a multi-disciplinary Core Clinical Center with experts from multiple clinical specialties, in addition to experts from the Southern California Clinical and Translational Science Institute (CTSI), the Leonard D. Schaeffer Center for Health Policy Economics, the USC CTSI Biostatistics and Bioinformatics Resource Group, and the USC Center for Body Computing.